NEET2026BiologyChapterActual
Which of the following best describes the primary structure of a protein?
Options
- AThe overall three-dimensional folding of a single polypeptide chain
- BThe positional information of amino acids in the polypeptide chain
- CThe spatial arrangement of two or more polypeptide subunits
- DThe local folding of the backbone into helices or pleated sheets
Correct answer
B. The positional information of amino acids in the polypeptide chain
Step-by-step solution
The primary structure of a protein refers to the linear sequence of amino acids in the polypeptide chain. It provides the positional information of each amino acid, indicating which amino acid is first, second, and so on. The local folding of the backbone into helices or pleated sheets refers to the secondary structure. The overall three-dimensional folding of a single polypeptide chain refers to the tertiary structure. The spatial arrangement of two or more polypeptide subunits refers to the quaternary structure.